In Simulation and Similarity, Michael Weisberg offers a similarity-based account of the model-world relation, which is the relation in virtue of which successful models are successful. Weisberg's main idea is that models are similar to targets in virtue of sharing features. An important concern about Weisberg's account is that it remains silent on what it means for models and targets to share features, and consequently on how feature-sharing contributes to models' epistemic success. I consider three potential ways of concretizing the concept of shared features: as identical, quantitatively sufficiently close, and sufficiently similar features. I argue that each of these concretizations faces significant challenges, leaving unclear how Weisberg's account substantially contributes to elucidating the relation in virtue of which successful models are successful. Against this background, I outline a pluralistic revision and argue that this revision may not only help Weisberg's account evade several of the problems that I raise, but also offers a novel perspective on the model-world relation more generally. 1Introduction2Weisberg's Feature-Sharing Account3What Is a Shared Feature? 3.1Identity3.2Sufficient closeness3.3Sufficient similarity4Turning Weisberg's Account 'Upside Down'5Conclusion.

© The Author(s) 2018. Published by Oxford University Press on behalf of British Society for the Philosophy of Science.